{"id":"F2006B06527","name":"AD/RAD/72 - Apollo SL30 VHF NAVCOM","slug":"ad-rad-72-apollo-sl30-vhf-navcom","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48171,"registerId":"commonwealth-F2006B06527-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.","sortOrder":0},{"sectionNumber":"AD/RAD/72 Apollo SL30 VHF NAVCOM 8/2001 ","sectionType":"part","heading":"AD/RAD/72 Apollo SL30 VHF NAVCOM 8/2001 TX","content":"# ![](image.003.png)AD/RAD/72 Apollo SL30 VHF NAVCOM 8/2001 TX\n\nApplicability: UPS Aviation Technologies, Inc., Model Apollo SL30 very-high-frequency navigation/communication (VHF NAVCOM) unit having Part Number (P/N) 430- 6040-300 or 430-6040-301.\n\nRequirement: 1. Determine what version of Digital Signal Processor (DSP) Software the Apollo SL30 VHF NAVCOM unit is using, in accordance with the following procedure:","sortOrder":1},{"sectionNumber":"Placing Unit In System Mode","sectionType":"part","heading":"Placing Unit In System Mode","content":"## Placing Unit In System Mode\n\nOperation Summary (Refer to page 4 of operation manual)","sortOrder":2},{"sectionNumber":"Power On","sectionType":"part","heading":"Power On","content":"## Power On\n\nTurn the SL30 on. Either turn the Power/Volume knob clockwise to turn the power on or, if installed, turn on the master switch that powers the radios. The SL30 will go through a short initialization routine and then briefly display the last VOR check date.\n\nSystem Info (Refer to page 26 of operation manual)\n\nSystem Info provides information about the Software versions and the Display Intensity.\n\n    Press SYS and turn the LARGE knob if necessary to the System Info page. Press ENT.\n\n    2. In the System Info function turn the LARGE knob to Nav Software Version.\n\n    3. Turn the SMALL knob to left (counterclockwise) to view DSP Software Version.\n\nNote 1: The procedure specified in Requirement 1 is identical to the \"PROCEDURE\" section of UPS Aviation Technologies, Inc., Service Bulletin SB2001-003, dated 29 June 2001.","sortOrder":3},{"sectionNumber":"\"USE OF SL30 VOR FUNCTION FOR NAVIGATION","sectionType":"part","heading":"\"USE OF SL30 VOR FUNCTION FOR NAVIGATION PROHIBITED.\"","content":"## \"USE OF SL30 VOR FUNCTION FOR NAVIGATION PROHIBITED.\"\n\n    b. Insert a copy of this Directive into the Limitations Section of the approved Aeroplane Flight Manual.\n\n    3. Apollo SL30 VHF NAVCOM units, having P/N 430-6040-300 or 430-6040-301 may not be installed on any aeroplane, unless the requirements of this Directive are accomplished.\n\nNote 2: FAA Emergency AD 2001-14-51 refers.\n\nCompliance: For Requirement 1 \\- Before further flight after the effective date of this Directive.\n\nFor Requirement 2 \\- Before further flight following the determination that Software Version Number 1.00 is installed.\n\nFor Requirement 3 - As of the effective date of this Directive. This Airworthiness Directive becomes effective on 5 July 2001.\n\nBackground: The United States Federal Aviation Administration (FAA) has received a report from the equipment manufacturer indicating that, during installation of an Apollo SL30 NAVCOM unit on an aeroplane, the installer noted that the radio was providing incorrect radial bearing information. Subsequent testing by the equipment manufacturer revealed that the bearing information was off by 14 degrees.\n\nThis incorrect bearing information has been attributed to an error in DSP Software Version Number 1.00. If the radio receives a signal from a VHF omnirange (VOR) ground station that deviates from the standard 30-Hertz signal, the error in the software causes the radio to incorrectly decode the bearing of the station. Because the occurrence of the error is dependent on the signal coming from a given station and not on the radio itself, the pilot may not know if the bearing information is incorrect.\n\nThis condition, if not corrected, could lead the pilot to use incorrect bearing information, which could result in inaccurate navigation information.","sortOrder":4}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The Directive is tightly focused on correcting a specific unsafe condition (incorrect VOR bearings caused by DSP Software Version 1.00). It does not expand beyond that safety objective. The installation prohibition and placarding are directly aligned with the stated purpose and do not broaden the Directive’s remit beyond preventing the identified unsafe condition."},"complexity_factors":["Short document (single AD) with limited sections: Applicability, Requirement, Compliance, Background","Few conditions: one software-version check and two conditional actions (placard/AFM amendment if version 1.00; installation prohibition)","Procedure is a simple user-menu check (System Info) rather than technical teardown","Cross-references to two external documents (UPS Service Bulletin SB2001-003 and FAA Emergency AD 2001-14-51) but no extensive cross-referencing into broader regulations","No multiple nested exceptions or layered subparts; timing conditions are straightforward (\"before further flight\", effective date)"],"plain_english_summary":"**What this directive does (mechanically)**\n\n- **Applies to**: Apollo SL30 VHF NAVCOM units with part numbers 430-6040-300 or 430-6040-301 (Applicability).\n- **Action required (Requirement 1)**: Before the aircraft flies again, the operator must check the unit’s Digital Signal Processor (DSP) software version by using the unit’s System Info menu (Procedure described under Requirement 1). The procedure matches UPS Aviation Technologies Service Bulletin SB2001-003 (Note 1).\n- **If DSP Software Version 1.00 is installed (Requirement 2)**: The VOR navigation function of that unit must not be used; a placard with the words \"USE OF SL30 VOR FUNCTION FOR NAVIGATION PROHIBITED\" must be fitted; and a copy of the Directive placed in the Aeroplane Flight Manual’s Limitations section.\n- **Installation ban (Requirement 3)**: From the effective date, those SL30 units (P/N 430-6040-300 or 430-6040-301) may not be installed on any aeroplane unless the Directive’s requirements have been complied with.\n- **Timing (Compliance)**: The software-version check (Requirement 1) must be done before further flight after the Directive’s effective date. If version 1.00 is found, the prohibitions and placarding (Requirement 2) must be done before further flight after that determination. The installation restriction (Requirement 3) is effective immediately as of the Directive.\n\n**Why it was issued (official rationale and technical cause)**\n\n- The FAA and the manufacturer reported that some Apollo SL30 units with DSP Software Version 1.00 can decode the bearing from a VOR (VHF omnirange) ground station incorrectly — by about 14 degrees — when the received station signal deviates from the standard 30 Hz signal (Background).\n- Because the error depends on the ground-station signal rather than an obvious radio fault, a pilot may not be aware the bearing is wrong. The Directive’s stated purpose is to prevent pilots using incorrect VOR bearing information (Background).\n\n**Who pays, who decides, and what behaviour changes**\n\n- **Who decides**: The CASA delegate issued the Directive under CAR 1998 subregulation 39.1(1) (front matter).\n- **Who pays / bears the burden**: Aircraft owners/operators are responsible for performing the software-version check, fitting placards, inserting the Directive in the flight manual, and arranging any required software update or replacement. If an upgrade or replacement is needed, the owner/operator bears that cost. Installers are restricted from fitting affected units unless requirements are met (Requirement 3).\n- **Behavioural changes required**: Operators must inspect radios before flight (until complied), stop using the SL30 VOR function if Version 1.00 is present, placard the aircraft, update AFM limitations, and avoid installing affected units without completing the Directive’s steps.\n\n**Implementation, costs and practical trade-offs**\n\n- **Compliance burden and likely costs**: The immediate burden is an inspection (menu check) that can be done by flight crew or maintenance staff. If Version 1.00 is present, additional actions (placarding, AFM amendment) are straightforward administrative steps; however, correcting the underlying software fault may require a manufacturer software update or unit replacement, which has direct monetary cost and aircraft downtime.\n- **Operational impact**: Operators who rely on VOR navigation from the SL30 will need an alternative means of VOR navigation in aircraft that have Version 1.00 installed until the unit is updated or replaced (Requirement 2). The installation prohibition (Requirement 3) prevents new installations of the affected P/Ns unless the Directive’s steps are already satisfied.\n- **Implementation risk**: The Directive relies on a simple, repeatable software-version check in the unit’s System Info menu. The risk is mainly practical: failure to carry out the check or to apply the placard/update where required could leave incorrect bearings in use.\n\n**Market and regulatory effects (light analytical lens)**\n\n- **Effect on private enterprise**: The Directive imposes compliance costs on aircraft operators and avionics installers. It constrains installers from fitting the specified SL30 P/Ns unless the Directive is complied with (Requirement 3). Manufacturers or authorised service providers likely capture any follow-on work to fix the software (upgrade or replacement), concentrating commercial benefit to those able to provide the remedy.\n- **Competition and choice**: Operators can choose to update the SL30, replace it with a different unit, or rely on alternate navigation sources. The Directive does not itself mandate which corrective supplier must be used, but practical fixes may be available only from UPS/authorised agents.\n- **Safety vs. downtime trade-off**: The measure trades a short period of inspection and, in some cases, device grounding or replacement, against the aviation safety risk arising from incorrect VOR bearings. The Directive’s requirements are narrowly targeted at that technical fault (Background and Requirements).\n\n**Source-located mechanics and references**\n\n- The required inspection procedure is the same as UPS Service Bulletin SB2001-003, dated 29 June 2001 (Note 1 under Requirement 1).\n- The Directive references FAA Emergency AD 2001-14-51 (Note 2).\n\n(Sections cited: Applicability; Requirement 1, 2 and 3; Compliance; Background; Notes 1 and 2.)"},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific software defect in a specific aviation radio model. It has not expanded beyond the immediate safety issue of incorrect VOR bearing calculation caused by DSP Software Version 1.00."},"complexity_factors":["Single, specific product applicability (only two part numbers)","Straightforward three-step compliance structure (identify, prohibit if affected, installation ban)","Clear procedural instructions with manual references (pages 4 and 26)","Simple conditional logic (only applies if Software Version 1.00 detected)","No nested definitions or extensive cross-referencing to other legislation","Single background cause (software error causing 14-degree bearing deviation)","Limited to one specific unsafe condition rather than multiple scenarios"],"plain_english_summary":"This AD requires operators of aircraft with the Apollo SL30 VHF NAVCOM (P/N 430-6040-300/301) to check the unit’s DSP software and, if it’s Version 1.00, immediately disable the VOR navigation function and update the flight manual to prohibit its use; new installations are barred until checked. Version 1.00 can misread certain VOR signals and produce a 14° bearing error, posing serious navigation and safety risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-rad-72-apollo-sl30-vhf-navcom","history":"/api/acts/ad-rad-72-apollo-sl30-vhf-navcom/history","analysis":"/api/acts/ad-rad-72-apollo-sl30-vhf-navcom/analysis","conflicts":"/api/acts/ad-rad-72-apollo-sl30-vhf-navcom/conflicts","importantCases":"/api/acts/ad-rad-72-apollo-sl30-vhf-navcom/important-cases","documents":"/api/acts/ad-rad-72-apollo-sl30-vhf-navcom/documents"}}